河南前河金矿蚀变岩磁化率特征与金矿化关系探讨

Relation between the characteristics of magnetic susceptibilities of altered rocks and gold mineralization in the Qianhe gold deposit, Henan

河南前河金矿为构造蚀变岩型金矿,矿体和围岩呈渐变接触关系,界线模糊,但矿体、围岩和各种蚀变岩的磁化率有着明显的差别,利用WCL-1便携接触式磁化率仪对前河金矿各中段和勘探线的蚀变岩进行了系统的磁化率测量,各典型蚀变岩的磁化率从大到小依次为,绿泥石化(Ch)→硅化绿泥石化(Si+Ch)→绿泥石化硅化(Ch+Si)→钾长石化(Kf)→硅化(Si)→黄铁绢英岩化(Py+Se+Si)。蚀变岩磁化率与其金矿化程度的相关性分析表明,二者总体上呈负相关的相关趋势。绘制了78和83勘探线的磁化率剖面图和矿区磁化率-金品位等值线垂直纵投影图,初步预测了矿区的深部找矿方向。

The Qianhe gold deposit, Henan, is of tectonic alteration type. In this deposit, orebodies show gradational contact relationships with wall rocks with a vague boundary, but there is distinct difference in magnetic susceptibility among orebodies, wall rocks and various types of altered rocks. Systematic susceptibihty measurements were made of altered rocks in various levels and along exploratory hnes of the Qianhe gold deposit using a WCL-1 portable contact magnetic susceptibility meter. The susceptibility values of various kinds of typical altered rocks are in decreasing order as follows： chloritized rocks （Ch） → silicified-chloritized rocks （Si＋ Ch） → chloritized-sihcified rocks （Ch＋Si） → K-feldspathized rocks （Kf） → silicified （Si） → pyritized-phyUic rocks （Py＋Se ＋Si）. Correlation analysis of the magnetic susceptibilities of altered rocks and degrees of gold mineralization indicates that there is a negative correlation trend between them. Profiles of magnetic susceptibilities of altered andesite along hnes 78 and 83 and a vertical longitudinal projection map of magnetic susceptibilities and gold grade isohnes in the ore district have been constructed, and the direction for looking for ore deposits at depth in the ore district has been predicted prehminarily.